Epilepsy is a brain disorder characterized by recurrent and spontaneous derangements of normal brain activity. More than 50 million people worldwide have epilepsy. Approximately 70% of patients with epilepsy can be successfully treated with anti-epileptic drugs (AEDs). For these cases of intractable epilepsy with seizures either resistant to drug treatment or unsuitable for surgery, alternative therapeutic approaches are needed.
Electrical stimulation has been explored as a potential for benefit in treating epilepsy. With varying degrees of success, several studies have examined the effects of continuous and periodic stimulation for controlling seizures. Results from studies of the NeuroPacer™ Responsive Neurostimulator System (RNS) and the stimulation of the anterior nuclei of thalamus for epilepsy (SANTE) demonstrate that deep brain electrical stimulation (DBS) can reduce the occurrence of seizures in select patient populations. In the RNS study, approximately 54% of the patients implanted with the device experience greater than 50% reduction in seizure frequency from pre-implantation period. Most stimulation paradigms in therapeutic devices seek to reduce the frequency of seizure onset but are not specifically tailored to terminate a seizure once ictal activity has initiated simply because past efforts at this goal have not yet shown strong efficacy. Most researchers derive stimulation parameters by trial and error and frequently use as a starting point the experience of DBS for treating movement disorders. There is a continuing need for a stimulation protocol to improve the effectiveness of DBS in stopping epileptic seizures.